In the production of holographic media, as described in U.S. Pat. No. 6,743,552, information is stored in a polymer layer which substantially consists of a matrix polymer and very special polymerizable monomers distributed uniformly therein. This matrix polymer may be based on polyurethane. It is prepared as a rule starting from NCO-functional prepolymers which are crosslinked with polyols, such as polyethers or polyesters, with urethane formation.
However, what is problematic is that optical impairment, such as opacity phenomena of the storage layer, frequently occurs owing to the incompatibilities between such urethane matrices and radiation-curing monomers.
Systems comprising polyisocyanates, polyols and radiation-curing compounds, such as photochemically crosslinking reactive diluents, are known in individual cases from the area of coating technology (U.S. Pat. No. 4,247,578, DE 197 09 560). Polyol components mentioned are substantially polyether- or polyester-based ones or polyacrylatepolyols. Nothing specific is stated regarding their compatibilities with the olefinically unsaturated compounds likewise present, such as acrylate-based reactive diluents.